At about 5am on 31st December, emergency services attended to a fire in an electrical cabinet in the Schwamendingen tram subway between Milchbuck and Tierspital. Although tram operation was resumed later that day, the fire had taken out the block signalling system. When driven on sight, the maximum speed in the tunnel is 18km/h (rather than 60km/h), and the tunnel lighting needs to be on.

I travelled through the tunnel on the evening of 6th January and the slow regime was still in force between Tierspital and Milchbuck. As a silver lining, the lighting reveals many details of the tunnel interior otherwise not seen.